openapi: Fix fetch_event_types param example in /register POST endpoint.
openapi: Fix fetch_event_types param example in /register POST endpoint.

shubhamdhama/zulip,hackerkid/zulip,kou/zulip,kou/zulip,kou/zulip,timabbott/zulip,shubhamdhama/zulip,hackerkid/zulip,rht/zulip,rht/zulip,eeshangarg/zulip,andersk/zulip,synicalsyntax/zulip,shubhamdhama/zulip,eeshangarg/zulip,brainwane/zulip,zulip/zulip,timabbott/zulip,hackerkid/zulip,showell/zulip,brainwane/zulip,showell/zulip,showell/zulip,punchagan/zulip,andersk/zulip,shubhamdhama/zulip,shubhamdhama/zulip,zulip/zulip,synicalsyntax/zulip,rht/zulip,hackerkid/zulip,timabbott/zulip,timabbott/zulip,kou/zulip,brainwane/zulip,punchagan/zulip,eeshangarg/zulip,zulip/zulip,hackerkid/zulip,eeshangarg/zulip,kou/zulip,brainwane/zulip,punchagan/zulip,zulip/zulip,timabbott/zulip,timabbott/zulip,hackerkid/zulip,brainwane/zulip,andersk/zulip,shubhamdhama/zulip,punchagan/zulip,eeshangarg/zulip,punchagan/zulip,punchagan/zulip,rht/zulip,eeshangarg/zulip,andersk/zulip,andersk/zulip,showell/zulip,kou/zulip,andersk/zulip,zulip/zulip,showell/zulip,synicalsyntax/zulip,showell/zulip,rht/zulip,punchagan/zulip,shubhamdhama/zulip,brainwane/zulip,zulip/zulip,rht/zulip,brainwane/zulip,zulip/zulip,synicalsyntax/zulip,timabbott/zulip,eeshangarg/zulip,showell/zulip,kou/zulip,rht/zulip,synicalsyntax/zulip,andersk/zulip,synicalsyntax/zulip,synicalsyntax/zulip,hackerkid/zulip